code: def widthChanged(self):
      sr = self.getSourceRect()
      ar = sr.height() / sr.width()
      self.params.param("height").setValue(
          self.params["width"] * ar, blockSignal=self.heightChanged
      )
  
file_path: pyqtgraph/pyqtgraph/exporters/PrintExporter.py
imports: from ..parametertree import Parameter
  from ..Qt import QtCore, QtGui, QtWidgets
  from .Exporter import Exporter
label_desc: Use image node_id 2 for calling the PrintExporter obj's underlying member method code with example usage: obj.widthChanged() without return types